The lone, bedrock certainty of any boxing career is that the boxer is the last one to know it’s over, when it’s time to hang up his gloves, sure that he’s square with the squared circle.

The twin narcotics of cash and cachet have plagued the aging boxer for as long as they’ve paid fighters to fight. They are perks at 25, but vices at 35. Nothing makes us wince like the old boxer in repose, fading under the dim lights of dementia.

The problem with that tableau is it doesn’t yet seem to apply to Mayweather. Especially Mayweather, who, at 38, still has his faculties, talent, and temerity. At least enough to keep cruising down a few more glittering paydays.

How does anyone walk away from that kind of quid? How many $100 million checks can a man cash? Very few humans will ever know the answer. But there is at least one more out there for the undefeated champion, whose financial appetite is renowned, often seen stuffing duffel bags with bricks of cash.

Mayweather said he made over $300 million in his 36 minutes of embellished sparring with Manny Pacquiao – a fight that was branded the fight of the young century, which came with an epic cable bill yet made us feel bilked.

Bu that’s what makes Mayweather such a pugilistic anomaly. He brings victory without violence. Like boxing quicksand, he lets you punch your way into suffocation. Hence he has hasn’t taken the expected battering of someone with his career arc.

It’s not absurd to suggest he has the body and brain of someone ten years his junior because he’s avoided the bruising body and head shots, and kept his physique relatively pristine. He shares none of the fighter’s enmity for fitness between bouts. He never visits the bar or buffet. He has no vice that poisons his stomach or spirit, and has avoided all the land mines that have exploded under so many famous feet.

Humans aren’t wired for the kind of success Mayweather has enjoyed for so long. We can’t process unlimited wealth, freedom, and fame, which is why so many bejeweled careers have crumbled shortly after the first monstrous contract or paycheck.

Maybe Mayweather wants to exhale. Jim Gray asked if there were some cuisine he’s coveted but avoided in the name of body fat. He didn’t answer. But with all the excess surrounding him, all the parties he sponsors yet never indulges, maybe he would like to get with some sin in Sin City.

But if it were in his nature to embrace the more tawdry flank of Las Vegas, he probably would have done so already. He spent his salad days eating salad, buried in the gym, his moonlit roadwork a hallmark of his empire.

Leonard Ellerbe told me in April that Mayweather would retire with nine-digits in the bank, before the Pacquiao bout. If true, then he doesn’t need to fight any more than he needs another space-age automobile.

But “Money” is his moniker. And when we ask the ancient question – what is enough? – we can’t use the normal metrics with Mayweather, who lives in a city with distorted values and a sport that’s still willing to make it rain on his reign, for however long he keeps winning.

And as someone with an epic sense of self, it’s hard to imagine Mayweather retiring tied with Rocky Marciano, at 49-0. Not with so much left in the tank, on the table, and with the monetary rails so greased for a rematch with Pacquiao. So maybe he makes $150 million instead of $300 million. If nothing else, it beats retiring after Andre Berto.

Jason writes a weekly column for CBS Local Sports. He is a native New Yorker, sans the elitist sensibilities, and believes there’s a world west of the Hudson River. A Yankees devotee and Steelers groupie, he has been scouring the forest of fertile NYC sports sections since the 1970s. He has written over 500 columns for WFAN/CBS NY, and also worked as a freelance writer for Sports Illustrated and Newsday subsidiary amNew York. He made his bones as a boxing writer, occasionally covering fights in Las Vegas, Atlantic City, but mostly inside Madison Square Garden. Follow him on Twitter @JasonKeidel.